Electric-resistance furnace.



A. PETERSS'ON.

ELECTRIC RESISTANCE FURNACE.

APPLICATION FILED MAY 25, 1910.

Patented Sept. 5, 1911 3 SHEETS-SHEET 1.

A. PETERSSON.

ELECTRIC RESISTANCE FURNACE.

APPLIOATION FILED MAY 25, 1910.

1,002,444. Patented Sept. 5, 1911.

3 SHEBTSrSHEET 2.

A. PETERSSON. ELECTRIC RESISTANCE FURNACE.

APPLIOATIQN FILED MAY 25, 1910.

Patented Sept15,1911.

3 BHEETSSHEET 3.

ALBERT PETERSSON, OF ODDA, NORWAY.

ELECTRIC-RESISTANCE FURNACE.

Specification of Letters Patent.

Patented Sept. 5, 1911.

Application filed May 25, 1910. Serial No. 568,312.

To all whom'it may concern Be it known that I, ALBERrPnrnRssoN, acitizen of the Kingdom of Sweden, residing at Odda, Norway, haveinvented new and useful Improvements in Electric-Resistance Furnaces, ofwhich the following is a specification.

This invention .relates to improvements in electric resistance furnaces.In such furnaces heretofore known, in which the current flows into thecharge from electrodes disposed in the upper part of the furnace indirect contact with the charge electric arcs may be formed at the endsof the up: per electrodes when the charge sinks down in the furnace oris melted in proximity to the said electrodes. By these arcs theresistance of the furnace is increased causing a high reduction of the"electric energy taken up by the furnace. At the same time thedistribution of heat in the charge will be unfavorable, the strongestheat being developed in the upper part of the furnace in proximity ofthe upper electrode or electrodes whereby thecha'rge is caused to melttoo early and to be partly gasified and the molten material is thrownout from the furnace. The wear of the electrodes will also be increasedwhen arcs are formed, while the consumption of the electrodes isunessential when the current flows directly to the charge from theelectrodes without forming arcs. v

The object of the present invention is to remove the said disadvantagesand it consists, briefly, in the provision in an electric.

resistance furnace'of means in the upper part of the furnacefon forcingcontinuously or intermittently the charge in a substantially horizontaldirection toward the upper electrode or electrodes of the furnace.Hereby the against the said electrode or electrodes pre venting theformation of arcs.

In the accompanying drawings I have shown some embodiments of myinvention. Figures 1-4 show vertical sections of different meltingfurnaces embodying the.

invention. Fig. 5 is a vertical section and Fig. 6 a horizontal sectionof a fifth construction form. Fig. 7 shows a vertical section and Fig. 8a horizontal section of a sixth construction form. Figs. 9 and 10 showvertical sections of modifications of the furnaces shown in Figs. 1 and3 respectively.

material charged will be pressed 1 filled with the charged material.form shown in Figs.

per

Referring to Fig. l, 1 indicates a bottom electrode and 2 an uppercentral electrode around whichthe material is charged. The disadvantageto be removed by the present invention consists in that air gaps areformed around the lower end of the electrode 2 when the charge sinks. Inorder to obviate this disadvantage, hoppers 3, 3 are provided atthesides of the furnace at the top of the latter, in which are arrangedfeed screws 4 which force the material in a substantially horizontaldirection toward the end of the electrode 2. Air-gaps that eventuallyare formed around the electrode 2 on account of the charge sinking downwill hereby be filled immediately so that the formation of arcs and thedevelopment of v.a toohigh heat in the upper part'of the furnace will beprevented.

differs from that shown in Fig. 1 only in that instead of the feedscrews pistons 5 are used, which force the material from the hoppers 3into the furnace. The working is substantially the same as thatdescribed with reference to Fig. l. I

Referring toFig. 3, pistons 6 are provided near to the upper edge of thefurnace wall, which maybe operated by hydraulic devices or suitablemechanical movements and serve to force the material introduced intotheupper part of the furnace from the furnace wall toward the centralelectrode 2. This device works substantially in the same manner as thosedescribed above.

In the form shown in Fig. 4 pivoted doors 7 are used instead of thepistons 6 air-gaps around the electrode 2 will be In the construction 5and 6 the upper portion 8 of the furnace wall is rotatable and providedat the inner side with cams 9 or the like. When the portion 8 is rotatedin the. direction indicated by the arrow in Fig. 6, the said cams will.force the charge toward the central electrode so that the lattercontinuously will be closely surrounded by the charge. The upportion 8vided with teeth 10 in which engage a toothed wheel 11 by means of whichthe said upper portion can be rotated. For this of the furnace may beprodriving device obviously other equivalent means may be substituted.

In the construction form shown in Figs. T and 8 the furnace is providedwith a bottom electrode 1 and two lateral electrodes 1:2 and 13 mountedin the upper part of the furnace wall. In this form the material isforced toward the said lateral electrodes 12 and 13 by means of acentral rotatable shaft ll reaching into the furnace and having a cam 15or the like which when the shaft is rotated, acts on the surroundingmaterial and forces the same toward the furnace wall and maintains thecontact between the charge and the lateral electrodes.

In the modifications shown in Figs. 9 and 10 the feeding devices 4 and 6respectively are disposed somewhat lower than in Figs. 1 and 3. Thehorizontal displacement of the charge, therefore, will take place towarda point below the ends of the electrode 2 so that the material onlyindirectly will be pressed against the said electrode. By thisarrangement air-gaps below the end of the electrode: 2 will be veryeasily filled,,.,'ip by the charge. Further, if the carbon and thematerial to be reduced, for instance lime, are charged un mixed into thefurnace and the carbon is placed in the next proximity of the electrode,the said latter material can more easily sink down in the furnace, thanif the horizontal pressure is exerted directly toward the electrode. Itis evident that the forms shown in Figs. 2 and 44 may also be modifiedin the same manner, if desirable. It is further obvious that the devicesdescribed above are only constructional forms of the invention, whichmay be varied in many ways without departing from the principle of theinvention.

Having now described my invention what I claim as new and desire tosecure by Letters Patent is:

1. An electric smelting furnace having a lower electrode and an upperelectrode and in which the charge forms a vertical resistance conductorbetween the electrodes,

in combination with means in the said upper part of the furnace forforcing the charge in a substantially horizontal direc tion toward saidupper electrode, for the purpose of avoiding electric arcs at the end ofthe said upper electrode.

2. An electric smelting furnace having an upper electrode and a lowerelectrode and in which the charge forms a vertical resistance conductorbetween the electrodes, in combination with plungers in the upper partof the furnace for forcing the charge in a substantially horizontaldirection toward said upper electrode for the purpose of avoidingelectric arcs at the end of the said upper electrode.

In testimony that I claim the'foregoing as my invention, I have signedmy name in presence of two subscribing witnesses.

ALBERT PETERSSON.

Witnesses:

F. W. BRUCE, J onem'v FAYE.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, I). C.

